i bought a 1990 ford f450 with the 7.3 diesel
i replaced the glow plugs and the module and solinoid. the glow plugs are getting 12v until the wait to start light goes out. then the solinoid just starts clicking and the voltage to the glow plugs goes on and off. it will just crank. if i spray it with eather it still takes a while to start. once running it will start everytime. anyone have any ideas. plz help thanks steve

 

sounds like your loosing your fuel prime.... dont use starting fluids..... those new glow plugs will blow up ... and you will have 1 hell of a time trying to retreive them from your cylinders.... possibly pull heads..... use marine fogging oil or even wd40 at worst.... no either

BAD IDEA !!!!!

 

what would cause it to loose prime

 

Air getting in fuel system...ether isn't horrible, just disable the glow plugs and little bursts in the intake while cranking you should be ok.

 

Mine is doin the same thing and its the fuel pump, my glow plugs arent stayin on for the 20 sec, so i just warm them up 4 times, let cool for 2 min, then spray wd40 in and warm up again and it cranks right up. As for what would cause the lift pump to lose pressure is the diapram will crack and bleed back in the feed line, and lots of cranking to get it started

 

you could have a crack in a fule line, fuel/water seperator bowl o-ring could be torn or distorted. if your loosing fuel prime after sitting for a good amount of time, could be a return fuel line from one of the injectors as well. I replaced all the fuel lines from the tank switch ... cured the problems entirely.

 

I replaced all my return lines, no craks in any of the main lines.

 

put a clear line between your lift pump and the fuel/water seperator... if you see any air bubbles .. you have a badfuel line some where if not you have an issue with the water seperator or your hard lines from the IP, or the IP its self
.. other than that .. no idea would have to hear it and see it my self

 

it runs good just if it sits, like you run it and shut it off, cause of the diaphram, it drains back and it takes forever to start, and thats warm. Gotta question for ya, would a weak fuel pump not let me pull a 25 ft gooseneck, in 4wd low range 2nd gear, Empty trailer.
(replaced all the return lines, all injectors are great shape, put a stephoscope to all my injectors, their all workin good, all my lines are nice and tight.

 

i thingk your IP might be waek or not adjusted right ... might be too lean on the fuel... ummmm..... or maybe u have a bad fuel tank switch or a leak in the lift pump... gonna have to put in some clear lines in a few key area's to find the sourse of the loss of prime.... I used my viedo cammera and a drop light and filmed mine over niight.... then just fast forward till i found the one that was leaking..... just used it llike 4 different nights....so between the water/fuel separator... the fuel lift pump and the line up to fuel water sep. .... and just after the tank switch.. forward twards the front ... on the supply line..... you will find an issue at some point..guarentee..... you caould also go between f/w sep and IP as well...... look for fuel leaks also... clean motor thourly and make sure its all dry .... the it might be obvious.... other wise I'm stumped...